Pipe repair

ABSTRACT

The present disclosure relates to a method for repairing a partially collapsed pipe. The method comprises fitting a mesh stent around the outside of an actuation assembly of a pipe repair apparatus, and positioning the pipe repair apparatus within a portion of the pipe, at least a part of the portion of the pipe being partially collapsed. The method also comprises causing actuation between a retracted configuration and an extended configuration such that the partially collapsed part of the pipe changes from a partially collapsed form towards a non-collapsed form. The method also comprises removing the pipe repair apparatus from the pipe and leaving the mesh stent in the portion of the pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to United Kingdom (GB) Application No.1818746.8, filed Nov. 16, 2018, the contents of which are incorporatedherein by reference in their entirety.

INTRODUCTION Technical Field

The present disclosure relates to pipe repair. More particularly, butnot exclusively, the present disclosure relates to repairing partiallycollapsed pipes using a pipe repair apparatus.

Background

Pipe repair includes work related to repairing subterranean pipes, suchas water pipes and sewage pipes.

Known methods involve use of an expander for straightening partiallycollapsed pipes. In some known methods, ‘rubber packing’ is used as theexpander, whereby the force against interior walls of the pipe that isbeing repaired is provided by pneumatic expansion of a rubber balloon.In some such known methods, while straightening the partially collapsedpipe, a coil shaped replacement pipe is fitted around the outside of theexpander and the coil shaped replacement pipe is expanded to fit withinthe damaged section of pipe. Other known methods involve use ofhydraulic actuation to expand a coil shaped replacement pipe.

International Patent Application No. WO 97/11306 discloses ahydraulically actuatable expander for straightening and repairingpartially collapsed pipelines. The expander comprises a plurality ofhydraulic pistons and expander segments and a synchronizing mechanismfor synchronizing the expansion. A flexible plate with overlapping edgesis arranged around the expander.

Korean Patent Application No. KR 20090056529 discloses a conduitrepairing apparatus. The conduit repairing apparatus has a deformationrestoration function in the form of an inflating member made of rubber.The apparatus involves the use of hydraulic cylinders and acylindrically rolled support plate that acts as a replacement pipe. Thesupport plate is coiled around the apparatus and ‘clicks’ into placeonce it reaches a specified diameter.

There are at least two issues with the state of the art as it stands.Firstly, the replacement pipe that remains coil shaped once fullyexpanded (i.e. comprises a section where it overlaps with itself) is notbeneficial if the pipe is to be relined. This overlapping portion isknown to interfere with the relining layer. In addition, the overlappingsection reduces the hydrodynamic conductivity of the pipe. This meansthat there is greater resistance to liquid flow in the pipe, and greaterpressure is required to obtain the same flow rate within the pipe.Secondly, the replacement pipe (or support plate) that uncurls andclicks in place must be prefabricated for the specific pipe diameter.This means that there must either be a large stock of different sizedsupport plates, or a longer wait-time (for example, for manufacture of aprefabricated stent) for repairing the pipe. A further issue is that ifthe pipe cannot be fully repaired, and only partially repaired,replacement pipes of this nature would be relatively useless as theywould be difficult or impossible to click into place.

It would therefore be desirable to provide improved methods forrepairing partially collapsed pipes.

BRIEF SUMMARY

According to embodiments, there is a method for repairing a partiallycollapsed pipe, the method comprising: fitting a mesh stent around theoutside of an actuation assembly of a pipe repair apparatus, theactuation assembly comprising a plurality of arms; positioning the piperepair apparatus within a portion of the pipe, at least a part of theportion of the pipe being partially collapsed; causing actuation, of atleast one of the arms in the plurality of arms, between a retractedconfiguration in which the at least one arm exerts substantially noforce against an interior surface of the pipe, and an extendedconfiguration in which the at least one arm extends outwards to exert aforce against the mesh stent and the interior surface of the pipe, suchthat the partially collapsed part of the pipe changes from a partiallycollapsed form towards a non-collapsed form; and removing the piperepair apparatus from the pipe and leaving the mesh stent in the portionof the pipe.

The method enables the partially collapsed pipe to be repaired withminimal or no excavation of the ground around the part of the pipe thatis partially collapsed. Access may for example be obtained via manholeslocated at opposite sides of the partially collapsed part of the pipe.Furthermore, it allows the pipe to be repaired quickly and without theneed for fitting a replacement pipe because the partially collapsed partof the pipe is pushed back towards a non-collapsed form and held in thisposition by the stent.

The method also minimizes disruption to human activities above groundbecause minimal or no excavation is involved, and hence there is minimalor no requirement to implement traffic control measures, or pedestriandiversions for example. Should these be involved, they would be in placefor the minimal duration of the repair. Furthermore, the use of a meshstent means that the mesh stent is able to substantially take the shapeof the portion of the pipe that is being repaired, and it provides auniform expansion. Use of a mesh stent means that even once expandedthere are no overlapping edges, and the circumference of thecross-section is a substantially smooth, continuous line. This providesthe added benefit that if the pipe were to be relined, there is lowerrisk of damage to the relining layer. In addition, the mesh stentaffords good hydraulic conductivity compared to alternative methods.

According to embodiments, there is a mesh stent for use in repairing apartially collapsed pipe.

According to embodiments, there is a pipe repair apparatus for use inrepairing a partially collapsed pipe.

According to embodiments, there is a computer program product comprisinga non-transitory computer-readable storage medium having computerreadable instructions stored thereon, the computer-readable instructionsbeing executable by a control module of a pipe repair apparatus, tocause the pipe repair apparatus to perform a method of repairing apartially collapsed pipe, the pipe repair apparatus having beenpositioned within a portion of the pipe, at least a part of the portionof the pipe being partially collapsed, a mesh stent having been fittedaround the outside of an actuation assembly of a pipe repair apparatus,the actuation assembly comprising a plurality of arms, the methodcomprising: causing actuation, of at least one of the arms in theplurality of arms, between a retracted configuration in which the atleast one arm exerts substantially no force against an interior surfaceof the pipe, and an extended configuration in which the at least one armextends outwards to exert a force against the mesh stent and theinterior surface of the pipe, such that the partially collapsed part ofthe pipe changes from a partially collapsed form towards a non-collapsedform.

It should be appreciated that features described in relation to oneembodiments of the present disclosure may be incorporated into otherembodiments of the present disclosure. For example, a method embodimentmay incorporate any of the features described with reference to anapparatus embodiment and vice versa.

DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described by way ofexample only with reference to the accompanying schematic drawings ofwhich:

FIG. 1 shows a perspective view of a pipe repair apparatus according toembodiments of the present disclosure;

FIG. 2 shows a perspective view of a pipe repair apparatus according toembodiments of the present disclosure;

FIG. 3 a shows a net of a mesh stent according to embodiments of thepresent disclosure;

FIGS. 3 b and 3 c show a formed cylindrical mesh stent accordingembodiments of the present disclosure;

FIGS. 4 a to 4 f schematically show how the stent is fitted onto theoutside of the actuation assembly, according to embodiments of thepresent disclosure;

FIG. 5 shows a perspective view of the pipe repair apparatus accordingto embodiments of the present disclosure;

FIG. 6 shows a perspective view of the pipe repair apparatus in asection of a pipe according to embodiments of the present disclosure;

FIG. 7 shows a perspective view of ISO Standard Quick release fittingsfor hydraulic connections according to embodiments of the presentdisclosure;

FIGS. 8 a to 8 h shows a schematic view of a pipe repair apparatusrepairing a partially collapsed pipe according embodiments of thepresent disclosure;

FIG. 9 shows the actuation of the pipe repair apparatus within a pipe,according to embodiments of the present disclosure; and

FIG. 10 shows a cross-sectional view of a pipe repair apparatusrepairing a partially collapsed pipe according to embodiments of thepresent disclosure.

DETAILED DESCRIPTION

It should be noted that in the following description and accompanyingfigures, like or the same reference numeral in different embodiments areused to denote the same or similar features.

FIG. 1 shows a pipe repair apparatus 100 for repairing a partiallycollapsed pipe according to embodiments of the present disclosure. Piperepair apparatus 100 comprises an actuation assembly 150. Actuationassembly 150 comprises one or more hydraulic cylinders 154 that areconnected to one or more actuation arms 152. The connection betweenhydraulic cylinders 154 and actuation arms 152 is provided by a numberof links 156 (per arm 152). In the example embodiments of FIG. 1 , threelinks 156 connect hydraulic cylinders 154 to respective arms 156, but inother embodiments, different numbers of links/arms are employed. Links156 are configured to work together, when connected to actuation arm152, to move outwards from actuation assembly 150 when hydrauliccylinders 154 are being actuated. Arms 152 are distributed around thecircumference of actuation assembly 150 (some of arms 152 are not shownhere as FIG. 1 has been drawn to show the inner workings of actuationassembly 150). When a force is applied through the hydraulic fluid intohydraulic cylinders 154, each of arms 152 move out simultaneously, withthe same force, and at the same speed.

In the embodiments depicted in FIG. 1 , pipe repair apparatus 100comprises a first wheel attachment 102 a for a first set of wheels 104 aat a first end, and a second wheel attachment 102 b for a second set ofwheels 104 b at a second end, opposite to the first end. Wheels 104 a,104 b are spaced evenly around the circumference of wheel attachments102 a, 102 b. This allows pipe repair apparatus 100 to be positioned inany orientation within a partially collapsed pipe that is beingrepaired, with one or more wheels of each set of wheels 104 a, 104 bbeing in contact with a bottom surface of the pipe. Wheels 104 a, 104 ballow pipe repair apparatus 100 to be moved easily within the pipe, andallows for precise positioning of pipe repair apparatus 100. Wheels 104a, 104 b also reduce the risk of pipe repair apparatus 100 being damagedby interior walls of the pipe.

In alternative embodiments of the present disclosure, one or more wheelsmay be removed from each wheel attachment for each set of wheels ifextra clearance is required within the pipe. Removing one or more wheelswould reduce the overall diameter of pipe repair apparatus 100 and thusallow it to fit into smaller spaces within the pipe. For example, if apartially collapsed part of the pipe reduced the diameter of the pipe toless than the diameter of pipe repair apparatus 100 with wheels 104 a,104 b, but larger than the pipe repair apparatus without wheels 104 a,104 b, removing at least one pair of wheels from the wheels 104 a, 104 bwould reduce the ride height of pipe repair apparatus 100 and allow itto fit within the partially collapsed part of the pipe. In alternativeembodiments of the present disclosure, arms of larger overall diametersare attached to the actuation assembly so that the pipe repair apparatuscan be used in pipes of larger diameter.

In alternative embodiments of the present disclosure, arms 152 do notmove simultaneously, or with the same force or speed. Instead, there maybe individual hydraulic lines (not shown) supplying each individualhydraulic cylinder 154. Some embodiments employ a control algorithm,along with a control mechanism for controlling the amount and force ofthe hydraulic fluid in each individual hydraulic line. Thus, each arm152 can be controlled independently. By use of such embodiments, more orless force can be applied to different segments of the pipecross-section where appropriate; for example, it may be more appropriateto apply less force in the horizontal direction compared to in thevertical direction. The control algorithm may also control and changethe amount of force supplied in each hydraulic line as a function of theresistance to movement that each arm 152 experiences within the pipeduring actuation of actuation assembly 150.

In alternative embodiments of the present disclosure, the arms 152 arenot hydraulically actuated, and the cylinders 154 are not hydraulic. Theactuation may comprise one or more of: hydraulic actuation, pneumaticactuation, and mechanical actuation. The cylinders may be pneumatic, andthe arms 152 may be pneumatically actuated, for example. Alternatively,the arms 152 may be mechanically actuated, and there may be no cylinder.Instead of a cylinder, the actuation assembly may comprise one or moreservo motors, for example.

FIG. 2 shows pipe repair apparatus 100 for repairing a partiallycollapsed pipe according to embodiments of the present disclosure. Piperepair apparatus 100 comprises actuation assembly 150 that comprisesfive hydraulic arms 152 (only four of which are visible in FIG. 2 ), allof which are connected via three links 156 each to actuation assembly150. Actuation assembly 150 is actuated and is in an extendedconfiguration. This can be seen because the diameter of actuationassembly 150 is greater than the overall diameter of first set of wheels104 a within wheel attachment 102 a. If actuation assembly 150 were inthe retracted configuration, then the diameter of actuation assembly 150would be less than the overall diameter of first set of wheels 104 awithin wheel attachment 102 a. In addition, if actuation assembly 150were to be in the retracted configuration, long edges of each arm 152 awould be in contact with—or in the least be very close to—an adjacentarm 152 b to provide a substantially continuous outer surface ofactuation assembly 150 with substantially no gaps between arms 152. Eachof the links 156 are connected to arms 152 via a pin joint (not shown).In embodiments, each arm 152 comprises a pin joint access hole 258 foreach pin joint. The pin joint access holes 258 facilitate easymaintenance and allow an operator to apply lubricant such as oil to thepin joint without having to deconstruct pipe repair apparatus 100.

In the embodiments of FIG. 2 , pipe repair apparatus 100 comprises apair of hydraulic lines 208 a, 208 b attached at the first end of piperepair apparatus 100. Hydraulic line 208 a is attached to pipe repairapparatus 100 via connector 210. The connector 210 allows hydraulic line208 a to transfer hydraulic fluid to and from pipe repair apparatus 100,and hence to and from the hydraulic cylinders (not shown). The hydrauliccylinders are double acting hydraulic cylinders, i.e. first hydraulicline 208 a transfers hydraulic fluid for actuating the actuationassembly 150 into the extended configuration, and second hydraulic line208 b transfers hydraulic fluid for actuating actuation assembly 150into the retracted configuration.

In embodiments, pipe repair apparatus 100 comprises a pair of first endtether attachment points 206. First end tether attachment points 206 areconfigured to be attached to a tether (not shown) such that pipe repairapparatus 100 can be pulled out of the pipe, for example on wheels 104a, 104 b, without putting any strain on hydraulic lines 208 a, 208 b.

The first end of pipe repair apparatus 100 also comprises a number ofbolts 212, 214 that secure wheels 104 a and wheel attachment 102 a tothe rest of pipe repair apparatus 100. To replace wheels 104 a, bothsets of bolts 212, 214 are removed, a retainer 216 is removed from piperepair apparatus 100, and wheels 104 a are then free to be replaced.

In alternative embodiments, only a single hydraulic line is connected topipe repair apparatus 100. In such embodiments, the single hydraulicline may only provide hydraulic fluid to actuation assembly 150 toactuate actuation assembly 150 into the extended configuration. Inalternative embodiments, the hydraulic cylinder may belong to a type ofhydraulic cylinders called spring return cylinders. The spring returncylinder of alternative embodiments comprises a spring that acts inopposition to the force provided by the hydraulic fluid, and when thereis substantially no force provided by the hydraulic fluid, the springcauses the hydraulic cylinder—and hence the actuation assembly—to returnto the retracted configuration. The spring of the spring return cylinderbiases the hydraulic cylinder, and actuation assembly 100, into theretracted configuration.

FIG. 3 a shows a net of a mesh stent 300 according to embodiments of thepresent disclosure. The net of the mesh stent 300 is formed of arepeating pattern of regularly spaced, solid, continuous, rectangularmetal portions 302, and regularly spaced, metal mesh portions 304,positioned in-between each of the rectangular portions 302. In theexample embodiments depicted in FIG. 3 a , there are five mesh portions304 in total in the net of the mesh stent 300, but other embodiments mayinvolve different numbers of mesh portions. The direction of the lengthdimension of the mesh stent is indicated by an arrow 330 and is definedas the direction parallel to the long edges of the rectangular portions302 (which are arranged parallel to each other). Mesh portions 304 areformed of a number of metal chevrons 306 nested within each other, witha gap in-between each chevron 306, along the length of the net of themesh stent 300. Each chevron 306 is connected, at its opposite edges, toan edge of an adjoining rectangular portion 302 located either side ofmesh portion 304. Each chevron 306 in a single mesh portion 304 is alsoconnected to an adjoining nested chevron by a continuous connectingstrip 308 that runs lengthwise relative to the net of the mesh stent 300and through a central line of symmetry (indicated by dashed line 332) ofchevrons 306. Connecting strip 308 ensures that each chevron 306 in eachmesh portion 304 moves uniformly when mesh stent 320 is being expanded.

In embodiments, at least one rectangular portion 302 comprises analignment portion 310 that is located on the line of symmetry that runsparallel to the long edge of each rectangular portion 302. Inembodiments of the present disclosure, the alignment portion 310comprises a bend, kink, or ridge. In alternative embodiments of thepresent disclosure, the net of the mesh stent may comprise alternativepatterns in the mesh portions. Such alternative patterns may for examplecomprise: a regular crenelated pattern for the mesh portion,interspersed by the same continuous rectangular portions 302; a singularmesh portion for the entire net, formed of repeated chevrons; a singularmesh portion for the entire net, formed of a crenelated pattern; asingular mesh portion for the entire net, formed of any suitablegeometric shape that can be tessellated to form a single mesh portion.Any of the aforementioned patterns may comprise a rectangular portionwhere the rectangular portions are either wider or narrower than themesh portions.

The net of the mesh stent 300 is rolled along its width and twocontinuous straight edges 310 a, 310 b are connected together to formmesh stent 320 of the embodiments depicted in FIG. 3 b . The connectionmay be formed by a weld, for example. Mesh stent 320 comprises asubstantially cylindrical cross-section.

The mesh stent according to embodiments of the present disclosure fitssnugly onto the outside of the actuation assembly. In alternativeembodiments of the present disclosure, the pipe may not be cylindricalin cross section, and may be oval or semi-circular. In such embodiments,the cross-section of the mesh stent may also be so designed tocorrespond to the cross-section of the pipe. The mesh stent may berigid. The mesh stent may be rigid in a non-expanded form and/or in anexpanded form. The expanded form may correspond to the extendedconfiguration of the plurality of arms. The mesh stent may comprisemetal. The mesh stent may comprise steel. Having a rigid mesh stenthelps ensure that the partially collapsed part of the pipe stays in thenon-collapsed form, after removal of the pipe repair apparatus from thepipe.

In embodiments of the present disclosure where at least one rectangularportion 302 comprises alignment portion 310, when net of mesh stent 300is rolled to form mesh stent 320, the alignment portions may form abend, kink, or ridge that protrudes outwards from mesh stent 320.

A perspective view of an end of mesh stent 320 is shown in theembodiments of FIG. 3 c . FIG. 3 c shows the cylindrical cross-sectionof mesh stent 320.

FIGS. 4 a to 4 f depict how mesh stent 320 is fitted onto the outside ofactuation assembly 150 to form pipe repair apparatus 400 according toembodiments of the present disclosure.

In embodiments of the present disclosure, fitting mesh stent 320 aroundthe outside of actuation assembly 150 comprises: removing one of morewheels of set of wheels 404 b from an end of pipe repair apparatus 400to allow mesh stent 320 to slide onto the outside of actuation assembly150; and reattaching the one or more wheels to the end of pipe repairapparatus 400. This process of fitting mesh stent 320 according toembodiments of the present disclosure is described in more detail below.

In the embodiments depicted in FIG. 4 a , end nut 418 is removed from asecond end of the pipe repair apparatus. This allows a second wheelattachment 402 b to be removed from the apparatus as shown in theembodiments of FIG. 4 b . Mesh stent 320 is then fitted over arms 152 ofactuation assembly 150 as shown in the embodiments of FIG. 4 c . Thelength of mesh stent 320 is only slightly shorter than the length ofarms 152 of actuation assembly 150, which allows for tolerance in themanufacture of the apparatus. The embodiments of FIG. 4 d show that themesh stent 320 has been pushed along the length of actuation assembly150 until the end of mesh stent 320 abuts against a first wheelattachment 402 a. The abutment occurs because the diameter of wheelattachment 402 a is greater than the diameter of actuation assembly 150(in the retracted configuration) and is also greater than the diameterof mesh stent 320 (also in the retracted configuration). Mesh stent 320is aligned on arms 152 of actuation assembly 150 such that eachrectangular portion 302 is centrally aligned over the alignment portion460 where the edges of each arm 152 meet. Alignment portion 310 of meshstent 320 is aligned with alignment portion 460, which is locatedequidistant between two arms 152 of the plurality of arms of the piperepair apparatus. This ensures that mesh stent 320 doesn't slidecircumferentially around the outside of actuation assembly 150, whichensures that mesh portions 304 are centrally aligned with arms 152 ofactuation assembly 150, ensuring optimal and uniform expansion of meshstent 320.

The embodiments of FIG. 4 e show that once mesh stent 320 has beenfitted, second wheel attachment 402 b is reattached onto the second endof pipe repair apparatus 400. Pipe repair apparatus 400 comprises a pin420, and second wheel attachment 402 b comprises a hole 422. Pin 420 isconfigured to fit within hole 422 when second wheel attachment 402 b isattached to pipe repair apparatus 400. This ensures that second wheelattachment 402 b is reattached in the correct orientation relative tothe rest of pipe repair apparatus 400. In embodiments of the presentdisclosure, FIG. 4 f depicts pipe repair apparatus 400 once second wheelattachment 402 b has been reattached, and nut 418 has been screwed backin place to secure second wheel attachment 402 b to the rest of piperepair apparatus 400.

In alternative embodiments of the present disclosure, the mesh stent isnot a similar length to the arms of the actuation assembly. Inalternative embodiments of the present disclosure, the mesh stent issignificantly shorter than the arms of the actuation assembly. The meshstent may for example be 75%, or 50%, or 25%, or any other suitablefraction of the length of the arms of the actuation assembly. An exampleof a reason for this is because the size of the portion of the pipe maybe significantly less than the length of the arms of the actuationassembly.

FIG. 5 shows a perspective view of pipe repair apparatus 400 accordingto embodiments of the present disclosure. Mesh stent 320 has been placedover arms 152 of actuation assembly 150, as described in the embodimentsof FIGS. 4 a to 4 f . In embodiments, pipe repair apparatus 400comprises lip 410. Lip 410 extends radially outwards from pipe repairapparatus 400, further than the diameter of mesh stent 320. Therefore,lip 410 ensures that mesh stent 320 does not move whilst pipe repairapparatus 400 is being positioned within pipe 500. Pipe repair apparatus400 is connected to hydraulic lines 408 a, 408 b for providing hydraulicfluid to actuation assembly 150. Hydraulic lines 408 a, 408 b areattached to the first end of pipe repair apparatus 400 where first wheelattachment 402 a for first set of wheels 404 a is located. Wheelattachment 402 a comprises first set of wheels 404 a. At the second endof pipe repair apparatus 400, second wheel attachment 402 b for secondset of wheels 404 b is located. Wheel attachment 402 b comprises secondset of wheels 404 b. Second wheel attachment 402 b also comprises asecond end tether attachment point 424. Second end tether attachmentpoint 424 is configured to be attached to a tether (not shown, butdescribed in relation to the embodiments of FIG. 8 ) for pulling piperepair apparatus 400 into the pipe and into position within a portion ofthe pipe, a part of which is partially collapsed.

In alternative embodiments of the present disclosure, a tether is notused to pull the pipe repair apparatus into the pipe, and instead eitherone or both sets of wheels of the pipe repair apparatus are motorized.Pipe repair apparatus 400 may comprise a wheel motor, and positioningpipe repair apparatus 400 within the pipe may comprise driving theset/sets of wheels 404 a, 404 b with the wheel motor. The set/sets ofwheels may be controlled externally by an operator, or it/they maycontrolled by an on-board control module. In embodiments of the presentdisclosure, the control module is programmed to position the pipe repairapparatus within the portion of the pipe, at least a part of which ispartially collapsed, by driving the set/sets of wheels. The pipe repairapparatus may comprise a battery, the battery being used to provideelectrical power to the motors that drive the set/sets of wheels. Itwill also be understood by the skilled person that in embodiments of thepresent disclosure, part of the maneuvering of the pipe repair apparatusmay be with a tether, and another part of the maneuvering may be withmotorized wheels: for example, in embodiments of the present disclosure,the tether is used to lower the apparatus into the pipe, and bring theapparatus most of the distance down the pipe; and motorized wheels areused to more finely position the pipe repair apparatus within a preciseportion of the pipe, at least a part of which is partially collapsed.

FIG. 6 shows a perspective view of pipe repair apparatus 400 within asection of pipe 500, according to embodiments of the present disclosure.Pipe 500 has illustratively had a section cut away so that pipe repairapparatus 400 can be seen in detail. Pipe repair apparatus 400 of theembodiments of FIG. 6 is the same pipe repair apparatus 400 as describedin the embodiments of FIG. 5 .

It can be seen that the overall diameter of pipe repair apparatus 400 isless than the inner diameter of pipe 500, so that pipe repair apparatus400 can move freely on its sets of wheels 404 a, 404 b along an inner,lower surface of pipe 500. Pipe repair apparatus 400 is in the retractedconfiguration, with mesh stent 320 fitted around the arms of theactuation assembly (not shown as hidden from view by stent 320).Hydraulic lines 408 a, 408 b connect pipe repair apparatus 400 to anexternal source of hydraulic fluid (not shown). The external source ofhydraulic fluid is external to pipe repair apparatus 400 and is outsideof pipe 500. The external source of hydraulic fluid also comprises apower source for pressurizing the hydraulic fluid within hydraulic lines408 a, 408 b such that actuation of the actuation assembly can takeplace. The hydraulic actuation is enabled by, and fluidly connected to,the hydraulic power source and/or hydraulic fluid source external to thepipe repair apparatus. According to embodiments of the presentdisclosure, the hydraulic fluid is chosen such that it does not have apollution risk should it leak into pipe 400. First wheel attachment 402a comprises a pair of first end tether attachment points 406. The pairof first end tether attachment points 406, in operation, are attached totethers (not shown) that feed out through pipe 500 to a winch (notshown) external to the pipe 500. These tethers are used to pull piperepair apparatus 400 out of pipe 500 through an opening, the openingbeing the route through which pipe repair apparatus 400 originallyentered pipe 500. Pipe repair apparatus 400 is not pulled by hydrauliclines 408 a, 408 b as this would put undue strain on hydraulic lines 408a, 408 b and may result in rupture and leakage of hydraulic fluid intopipe 500.

In alternative embodiments of the present disclosure, the source ofhydraulic fluid is located within the pipe repair apparatus itself.Keeping the source of hydraulic fluid external to the pipe repairapparatus may allow for a reduction in the weight of the pipe repairapparatus. However, having the source of hydraulic fluid within the piperepair apparatus would eliminate the need for hydraulic lines that runthrough the pipe. This means that there are no hydraulic lines that mayget snagged on rough surfaces within the pipe, and also means,therefore, that there are no hydraulic lines that are at risk of ruptureand leakage of hydraulic fluid. In alternative embodiments of thepresent disclosure, the power source may also be located within the piperepair apparatus. This also means that there is no risk of a power cablebeing snagged within the pipe. Again, this would increase the weight ofthe pipe repair apparatus, so such an inclusion of a power source withinthe pipe repair apparatus involves a trade-off.

FIG. 7 shows a quick release fitting 600 for hydraulic connectionsaccording to embodiments of the present disclosure. In embodiments ofthe present disclosure, quick release fitting 600 is used to connect twosections of hydraulic lines 608 a, 608 b together. Quick release fitting600 conforms to an ISO standard. Quick release fitting 600 comprises amale portion 626 and a female portion 628. Male portion 626 and femaleportion 628 are fitted together by pushing the two portions together. To‘lock’ the two portions together, a collar 628 a of female portion 628is rotated once the two portions are connected in place. The section ofhydraulic line 608 a that is connected to female portion 628 may beattached to a pipe repair apparatus, and the section of hydraulic line608 b that is connected to male portion 626 may extend to a source ofhydraulic fluid (and power source), for example.

FIGS. 8 a to 8 h show a schematic representation of pipe repairapparatus 400 repairing a partially collapsed pipe according toembodiments of the present disclosure. Embodiments of the presentdisclosure comprise a method for repairing a partially collapsed pipe,the method comprising: fitting mesh stent 320 around the outside ofactuation assembly 150 of pipe repair apparatus 400, actuation assembly150 comprising a plurality of arms 152; positioning pipe repairapparatus 400 within portion of the pipe 550, at least a part 552 ofportion 550 of pipe 500 being partially collapsed; causing actuation, ofat least one of arms 152 in the plurality of arms, between a retractedconfiguration in which the at least one arm 152 exerts substantially noforce against an interior surface of pipe 500, and an extendedconfiguration in which the at least one arm 152 extends outwards toexert a force against mesh stent 320 and the interior surface of pipe500, such that partially collapsed part 552 of pipe 500 changes from apartially collapsed form towards a non-collapsed form; and removing piperepair apparatus 400 from pipe 500 and leaving mesh stent 320 in portion550 of pipe 500. The non-collapsed form may be substantially cylindricalin shape.

The embodiments of FIG. 8 a show a pipe 500, within which there is aportion of pipe 550 where pipe repair apparatus 400 is arranged to bepositioned. A part 552 of the portion 550 is partially collapsed. Pipe500 comprises first and second openings 502, 504 to the surface. In someembodiments of the present disclosure, the openings are existingmanholes. A second tether 432 is run from a second winch 802 throughsecond opening 504, through pipe 500, and out first opening 502. Secondtether 432 is then attached to second end tether attachment point 424(not shown) on pipe repair apparatus 400. A first tether 430 is run froma first winch 800 and attached to first end tether attachment point 406(not shown). Also provided outside of pipe 500 is a ‘push and look’camera system 700, which comprises a camera module 750. A loweringsystem 900 is provided at first opening 502.

The embodiments of FIG. 8 b show that prior to putting pipe repairapparatus 400 into pipe 500, pipe repair apparatus 400 is first attachedby its first end to a lowering system tether 902 at the top of loweringsystem 900, the second end of pipe repair apparatus 400 hanging directlyabove first opening 502.

The embodiments of FIG. 8 c show that lowering system 900 lowers piperepair apparatus 400 via lowering system tether 902 into first opening502, into pipe 506. Pipe repair apparatus 400 is arranged so that it ishorizontally aligned within pipe 500.

The embodiments of FIG. 8 d show that pipe repair apparatus 400 is beingpositioned within portion of pipe 550. The positioning of pipe repairapparatus 400 (and hence actuation assembly 150) within the portion ofpipe 550 comprises rolling the pipe repair apparatus along the set ofwheels 404 a, 404 b. Lowering system tether 902 has been removed frompipe repair apparatus 400. The adjustment to the position of pipe repairapparatus 400 is made by either pulling of second tether 432, or pullingof first tether 430. The pulling of tethers 430, 432 is facilitated bywinches 800, 802 respectively. Positioning pipe repair apparatus 400within portion of the pipe 550 comprises pulling pipe repair apparatus400 via either first tether 430 or second tether 432 attached to arespective tether attachment point (406, 424, respectively). Winches800, 802 are controlled by an operator (not shown) positioned outside ofpipe 500. ‘Push and look’ camera system 700 pushes camera module 750into pipe 500 just ahead of portion of the pipe 550, so that cameramodule 750 observes portion of the pipe 550 and the second end of piperepair apparatus 400. Camera module 750 transmits a video feed inreal-time to the operator, such that the operator can make adjustmentsto the position of pipe repair apparatus 400 quickly and without theneed for manual inspection of pipe 500. In the embodiments depicted inFIG. 8 d , pipe repair apparatus 400 is positioned within portion of thepipe 550, and directly beneath the center of the part of the pipe thatis partially collapsed 552.

In the embodiments of FIG. 8 e , pipe repair apparatus 400 (as a resultof the actuation assembly) has moved between the retractedconfiguration, in which at least one arm 152 exerts substantially noforce against the interior surface of pipe 500, to an extendedconfiguration, in which at least one arm 152 extends outwards to exert aforce against mesh stent 320 and the interior surface of pipe 500 suchthat the partially collapsed part of the pipe 552 changes from apartially collapsed form towards a non-collapsed form, and back to theretracted configuration. Stent 320 has been expanded and the part of thepipe that was partially collapsed 552 has been pushed outwards such thatportion of the pipe 550 changes towards a non-collapsed form. Stent 320takes the shape of portion of the pipe 550 and holds it in place, suchthat part of the pipe 552 does not re-collapse. Stent 320 has beenpermanently deformed and holds portion of the pipe 550 at substantiallythe same diameter as the rest of pipe 500. When portion of the pipe 550is in the partially collapsed form, mesh stent 320 comprises anon-expanded form having a first diameter, and when portion of the pipe550 is in the non-collapsed form, mesh stent 320 comprises an expandedform having a second diameter, the second diameter being larger than thefirst diameter. In alternative embodiments of the present disclosure,the portion or the pipe is fully repaired. In these alternativeembodiments, the second diameter is approximately equal to a diameter ofpipe 500 in the non-collapsed form. Camera module 750 in this stage ofthe repair transmits a video in real time to an operator so that theoperator can control when the actuation of the actuation assembly (andhence the arms of the actuation assembly) has ceased, and when the armsof the actuation assembly need to be retracted. Camera module 750 allowsthe operator to know when part of the pipe that is partially collapsed552 has been repaired to a non-collapsed form.

Mesh stent 320 comprising a non-expanded form and an expanded formallows the arms of the actuation assembly to, when exerting a forceagainst the mesh stent, cause expansion of mesh stent 320. Mesh stent320, once expanded, will be pressed against the interior surface ofportion of the pipe 550, holding it in place. In embodiments of thepresent disclosure, mesh stent 320 deforms. The deformation may, forexample, comprise plastic deformation, such that once in the expandedform, it does not inherently return to the non-expanded form. In theseembodiments, mesh stent 320 can be left in place once the partiallycollapsed part of the pipe 552 has been changed towards thenon-collapsed form, and the mesh stent will hold part of the pipe 552 inposition and prevent it from returning to the collapsed form. Mesh stent320 holds the part of the pipe 552 in place while a relining layer canthen be fitted to at least the portion of the pipe 550.

In the embodiments of FIG. 8 f , pipe repair apparatus 400 has beenpulled back towards first opening 502 by first tether 430, which iswound in by first winch 800. Lowering system tether 902 has beenreattached to the first end of pipe repair apparatus 400. It can be seenthat stent 320 has been left in place, in an expanded form, in portionof the pipe 550. Camera module 750 has been wound back in by ‘push andlook’ camera system 700.

The embodiments of FIG. 8 g show that lowering system 900 has pulledpipe repair apparatus 400 out of pipe 500.

In the embodiments of FIG. 8 h , lowering system tether 902 has beendetached from pipe repair apparatus 400 and tethers 430, 432 can now beremoved from pipe repair apparatus 400. In alternative embodiments ofthe present disclosure, a second mesh stent is fitted onto the outsideof the actuation assembly in the event that part of the pipe that ispartially collapsed 552 is longer than the length of the first meshstent 320. Then the whole procedure as detailed in the embodiments shownin FIGS. 8 a to 8 h would be repeated. This is shown in more detail inthe embodiments of FIG. 10 .

In alternative embodiments of the present disclosure, camera module 750is not used, and instead pipe repair apparatus 400 comprises a system ofsensors (and/or a camera) that enables the operator to know when part ofthe pipe that is partially collapsed 552 has been changed sufficientlyfrom a partially collapsed form towards a non-collapsed form. Inalternative embodiments of the present disclosure, an on-board controlmodule is included in pipe repair apparatus 400. The on-board controlmodule is configured to monitor the distance by which at least one ofthe arms of the actuation assembly has moved. In this manner, theon-board control module can instruct the actuation assembly to ceasefurther movement of the at least one arm of the actuation assembly oncethe distance monitoring indicates that the at least one arm has moved apredetermined distance. The predetermined distance corresponds to anoverall diameter of the actuation assembly in the extended configurationthat corresponds to the diameter of pipe 500 in its non-collapsed form.The cessation of movement of the arm acts as a safety feature, ensuringthat the arms of the actuation assembly cannot be actuated to a distancethat corresponds to a diameter greater than the internal diameter of thepipe in the non-collapsed form. This feature prevents over-expansion ofthe apparatus, stent, and portion of the pipe, preventing further damageto the partially collapsed part and non-collapsed pipe.

In alternative embodiments of the present disclosure, the operator (oruser) controls and causes actuation of the actuation assembly via acontrol interface, by providing user input to the control interface,i.e. causing the actuation comprises receiving user input via thecontrol interface. The control module of the pipe repair apparatus ofsome embodiments receives the user input from the control interface. Inresponse to receipt of the user input at the control module, the controlmodule may instruct the actuation assembly to move between the retractedconfiguration and the extended configuration. In alternative embodimentsof the present disclosure, the control interface comprises a wired orwireless electronic remote control. The control interface transmits theuser input wired or wirelessly to the control module of the pipe repairapparatus.

In embodiments of the present disclosure, the apparatus comprises one ormore cameras configured to monitor positioning of the pipe repairapparatus in the pipe, and wherein in response to a user input receivedfrom a user viewing the camera at the control interface, the controlinterface instructs the actuation assembly to cease further movement ofat least one arm.

Viewing of the camera at the control interface allows the operator tocontrol the pipe repair apparatus while receiving visual feedback fromtheir inputs in real time. This means that there is no need to inspectthe pipe after the repair method has been performed, thus saving time.

The control module of alternative embodiments of the present disclosureexecutes a computer program comprising a set of instructions. The set ofinstructions may cause actuation of at least one of the arms of theactuation assembly, between a retracted configuration, and an extendedconfiguration, such that the partially collapsed part of the pipechanges from a partially collapsed form towards a non-collapsed form.

The embodiments of FIG. 9 show a view that camera module 750 can seewhen inside pipe 500, as in the embodiments of FIG. 8 e . This viewobserves the second end of pipe repair apparatus 400. The view shown onthe left of FIG. 9 is when pipe repair apparatus 400 is in the retractedconfiguration. On the right, the pipe repair apparatus is in theextended configuration. In this configuration, the arms 152 have beenactuated and are extending outwards to exert a force against theinterior surface of pipe 500. In the embodiments of FIG. 9 , pipe 500 isin a non-collapsed form, the non-collapsed form being substantiallycylindrical in shape. In alternative embodiments of the presentdisclosure, pipe 500 is a shape that is non-cylindrical. Pipe 500 may bea semi-circular, or an oval, for example.

FIG. 10 shows how pipe repair apparatus 400 can be used to repair partof the pipe that has been partially collapsed 552 that is longer thanthe length of stent 320, according to embodiments of the presentdisclosure. First, the process as detailed in the embodiments of FIGS. 8a to 8 h are performed. A difference in these embodiments is thatportion of the pipe 550 in which the pipe repair apparatus is positionedonly contains a section of part of the pipe that is partially collapsed552. Portion of the pipe 550 overlaps with some pipe 500 that is in thenon-collapsed form. This is so that when the stent is expanded, itprovides more tolerance for error in the positioning, and morestructural integrity surrounding the partially collapsed sections ofpipe.

Once a section of part of the pipe that is partially collapsed 552 hasbeen repaired, a second stent 322 is loaded onto the actuation assemblyand the process of the embodiments of FIGS. 8 a to 8 h is againrepeated. This time, however, the portion 556 overlaps: a part of wherefirst stent 320 was placed within the pipe 500; the remaining part ofthe pipe that is partially collapsed 554; and a section of pipe 500 thatis in the non-collapsed form. In this manner, part of the pipe that ispartially collapsed 552 can be any length, and pipe repair apparatus 400can be used to repair these partially collapsed parts by usingsuccessively deployed stents 320 to accommodate the length.

Whilst the present disclosure has been described and illustrated withreference to particular embodiments, it will be appreciated by those ofordinary skill in the art that the present disclosure lends itself tomany different variations not specifically illustrated herein. By way ofexample only, certain possible variations will now be described.

In alternative embodiments of the present disclosure, after pipe 500 hasbeen repaired as described above, a relining layer is fitted to at leastportion of the pipe 550 after pipe repair apparatus 400 has been removedfrom pipe 500. Portion of the pipe 550 comprises (formerly) partiallycollapsed part of the pipe 552, and at least one mesh stent 320 in anexpanded form. In embodiments of the present disclosure, the relininglayer is fitted inside of the mesh stent. In embodiments of the presentdisclosure, the relining layer overlaps both the inner surface of meshstent 320, and the inner surface of pipe 500, the inner surface of pipe500 being in the non-collapsed form. The relining layer may comprise acured-in-place pipe (CIPP). CIPP is compatible with trenchless repairoperations, and may extend the lifetime of pipe 500 compared to withoutthe use of CIPP. Due to the nature of some collapses, it may not bepossible to apply CIPP immediately.

The use of a relining layer provides extra structure to the pipe, andimproves the durability and lifetime of the pipe. The use of CIPPensures that the part of the pipe that was partially collapsed iswaterproof Fitting CIPP is also a trenchless operation, meaning that noexcavation is required of the pipe.

The second alignment portion may be located equidistant between two armsof the plurality of arms of the pipe repair apparatus. This helpsprevent the mesh stent sliding circumferentially around the outside ofthe actuation assembly, such that the mesh portions are centrallyaligned with the arms of actuation assembly, thus providing optimal anduniform expansion of the mesh stent.

Alternative embodiments of the present disclosure comprise a computerprogram comprising a set of instructions, which, when executed by acontrol module of a pipe repair apparatus, cause the computerized deviceto perform a method of repairing a partially collapsed pipe, the piperepair apparatus having been positioned within a portion of the pipe, atleast a part of the portion of the pipe being partially collapsed, amesh stent having been fitted around the outside of an actuationassembly of a pipe repair apparatus, the actuation assembly comprising aplurality of arms, the method comprising: causing actuation, of at leastone of the arms in the plurality of arms, between a retractedconfiguration in which the at least one arm exerts substantially noforce against an interior surface of the pipe, and an extendedconfiguration in which the at least one arm extends outwards to exert aforce against the mesh stent and the interior surface of the pipe, suchthat the partially collapsed part of the pipe changes from a partiallycollapsed form towards a non-collapsed form.

What is claimed is:
 1. A method for repairing a partially collapsed pipe, the method comprising: fitting a mesh stent around the outside of an actuation assembly of a pipe repair apparatus, the actuation assembly comprising a plurality of arms; positioning the pipe repair apparatus within a portion of the pipe, at least a part of the portion of the pipe being partially collapsed; causing actuation, of at least one arm of the plurality of arms, between a retracted configuration in which the at least one arm exerts substantially no force against an interior surface of the pipe, and an extended configuration in which the at least one arm extends outwards to exert a force against the mesh stent and the interior surface of the pipe, such that the partially collapsed part of the pipe changes from a partially collapsed form towards a non-collapsed form; and removing the pipe repair apparatus from the pipe and leaving the mesh stent in the portion of the pipe such that the partially collapsed part of the pipe is held in the non-collapsed form by the mesh stent.
 2. The method according to claim 1, comprising fitting a relining layer to at least the portion of the pipe after the pipe repair apparatus has been removed from the pipe.
 3. The method according to claim 2, wherein the relining layer is fitted inside of the mesh stent.
 4. The method according to claim 1, wherein, when the portion of the pipe is in the partially collapsed form the mesh stent comprises a non-expanded form having a first diameter, and when the portion of the pipe is in the non-collapsed form the mesh stent comprises an expanded form having a second diameter, the second diameter being larger than the first diameter.
 5. The method according to claim 4, wherein the second diameter is approximately equal to a diameter of the pipe in the non-collapsed form.
 6. The method according to claim 1, wherein the actuation comprises one or more of: hydraulic actuation, pneumatic actuation, or mechanical actuation.
 7. The method according to claim 1, wherein causing the actuation comprises receiving a user input via a control interface, and wherein the user input is received by a control module of the pipe repair apparatus, the method comprising: in response to receipt of the user input at the control module, the control module instructs the actuation assembly to move between the retracted configuration and the extended configuration.
 8. The method according to claim 7, wherein the control module is configured to: monitor a distance by which the at least one arm has moved; and instruct the actuation assembly to cease further movement of the at least one arm once the distance monitoring indicates that the at least one arm has moved a predetermined distance, the predetermined distance corresponding to a diameter of the pipe in the non-collapsed form.
 9. The method according to claim 1, wherein positioning the actuation assembly within the portion of the pipe comprises rolling the pipe repair apparatus along the pipe on a set of wheels.
 10. The method according to claim 9, wherein fitting the mesh stent around the outside of the actuation assembly comprises: removing one or more wheels of the set of wheels from an end of the pipe repair apparatus to allow the mesh stent to slide onto the outside of the actuation assembly; and reattaching the one or more wheels to the end of the pipe repair apparatus.
 11. The method according to claim 1, wherein the pipe repair apparatus comprises a wheel motor, and wherein positioning the pipe repair apparatus within the pipe comprises driving a set of wheels with the wheel motor.
 12. The method according to claim 1, wherein the pipe repair apparatus comprises a tether attachment point, and wherein positioning the pipe repair apparatus within the portion of the pipe comprises pulling the pipe repair apparatus via a tether attached to the tether attachment point.
 13. The method according to claim 1, wherein the actuation comprises hydraulic actuation, the hydraulic actuation being enabled by, and fluidly connected to, a hydraulic power source and/or hydraulic fluid source external to the pipe repair apparatus.
 14. The method according to claim 1, wherein the pipe repair apparatus comprises one or more cameras configured to monitor positioning of the pipe repair apparatus in the pipe, and wherein in response to a user input received from a user viewing the one or more cameras at a control interface, the control interface instructs the actuation assembly to cease further movement of the at least one arm.
 15. The method according to claim 1, wherein the mesh stent comprises a substantially symmetrical cross-section.
 16. The method according to claim 1, wherein the mesh stent comprises a first alignment portion, wherein the pipe repair apparatus comprises a second alignment portion, and wherein the fitting comprises aligning the first alignment portion with the second alignment portion.
 17. The method according to claim 16, wherein the first alignment portion comprises at least one of a bend, a kink, or a ridge.
 18. A computer program product comprising a non-transitory computer-readable storage medium having computer-readable instructions stored thereon, the computer-readable instructions being executable by a control module of a pipe repair apparatus, to cause the pipe repair apparatus to perform a method of repairing a partially collapsed pipe, the pipe repair apparatus having been positioned within a portion of the pipe, at least a part of the portion of the pipe being partially collapsed, a mesh stent having been fitted around the outside of an actuation assembly of a pipe repair apparatus, the actuation assembly comprising a plurality of arms, the method comprising: causing actuation, of at least one arm of the plurality of arms, between a retracted configuration in which the at least one arm exerts substantially no force against an interior surface of the pipe, and an extended configuration in which the at least one arm extends outwards to exert a force against the mesh stent and the interior surface of the pipe, such that the partially collapsed part of the pipe changes from a partially collapsed form towards a non-collapsed form and the partially collapsed part of the pipe is held in the non-collapsed form by the mesh stent. 